Hi Medley,
it means that you have download the Mac CUDA version, instead of the Mac Metal version that works with AMD GPUs under Catalina 10.15.7.
Please, remove the installed version, and download and install OctaneX for C4D PR3.
You can find it by visiting your personal Downloads area:
https://render.otoy.com/account/download_archive.phpYou need to select your purchased version from the Select Software pop up:
Then, please go to c4d menu Extensions/Console, (Shift+F10), and share a complete screenshot of the panel, thanks.
Please, also share a screenshot like this one, that shows both the c4doctane directory opened, and the entire installation path, thanks:
ciao Beppe